Cardio calculator
Heart-rate zones calculator
Get your max heart rate and the five training zones from your age. Free, instant, no sign-up.
Most endurance gains come from Z2 — the coach builds a plan that uses these zones.
What are heart-rate zones?
Heart-rate zones split your effort into five bands as a percentage of your maximum heart rate — from easy recovery (Z1) up to all-out (Z5). Training in the right zone for each session is what makes a plan work instead of just making you tired.
How this calculator works
We estimate max heart rate two ways — the textbook 220 − age and the more accurate Tanaka 208 − 0.7·age — then carve the five zones as percentage bands: Z1 50–60%, Z2 60–70%, Z3 70–80%, Z4 80–90%, Z5 90–100%.
Using your zones
The big one is Zone 2 — most aerobic base is built there, slower than most people run. Threshold and VO2 work (Z4–Z5) get sprinkled in for speed. The coach takes your zones and lays out the weekly mix so you're not guessing how hard to go.